Regioselective ring opening and isomerization reactions of 3,4-epoxyesters catalyzed by boron trifluoride.

Efficient ring opening of 3,4-epoxyesters with alcohols to produce 4-alkoxy-3-hydroxyesters and their isomerization into 4-ketoesters using boron trifluoride as the catalyst are presented. Both transformations are simple and efficient methods for the synthesis of the above named synthetically useful compounds.